Stray Rescue shared the letter on its Facebook page Monday along with a picture of the dog, Shell.

The woman said her own mother adopted Shell from Stray Rescue some eight or nine years ago. When her mother suffered a stroke and developed Alzheimer’s, Shell came to live with the woman.

In the letter, the woman explains she was recently diagnosed with cancer and has to part with her dog.

The woman’s name did not appear in the portion of the letter made public and Stray Rescue did not identify her. Stray Rescue presented the letter with a picture of Shell and asked perspective adopters to fill out an application.